A variety of flexible ladders and the like have long existed for use in various emergency situations, a prime example of which is use for escape from burning buildings. Among other things, the prior art includes a variety of rope ladders, ladders with rigid rungs connected by ropes or chains, flat bands intended for use in descending, and other structures which can be collapsible for storage purposes.
Many of the prior art devices have significant disadvantages and shortcomings and there is a need for innovation in the field. For some devices, collapsing for compact storage is problematic or has disadvantages. There may be difficulty in unfurling the structure for use in a time of emergency, with susceptibility to problems such as tangling. Certain prior disclosures of flat band devices have problematic slit-like features which can tend to pose difficulties for persons trying to lower themselves—problems related to difficulty in securing proper foot engagement with the device. Excessive flexibility is another problem, as is limited capability for dealing concurrently with multiple persons seeking to escape, e.g., from a burning building. Furthermore, it is noted that potential revisions of prior structures for the purpose of alleviating certain problems can introduce or exacerbate other problems.
An important issue for any escape ladder is its immediate availability in fully operative condition in case of emergencies, which may happen decades after installation. Such availability can be achieved by storing escape ladders immediately next to windows or on the roof of a building in such a way that, when needed, the ladder can be dropped down for evacuation. Certain collapsible ladders may tend not to withstand long-term outdoor storage because of being susceptible to rot, rust and other types of destruction. Prior art ladders may need to be covered by protective structure outside.
In summary, there is a need for an improved collapsible ladder that overcomes some of the problems and shortcomings of the prior art, and provides highly reliable fire-escape apparatus.